Christianity came to Finland in the 12th century. St Henry is the patron saint and first bishop of Finland. At the time of the Reformation in the 16th century Finland was part of the kingdom of Sweden. The Evangelical Lutheran Church regards itself as the natural successor of the church that existed in Finland before the Reformation. There was no radical break with the past. A certain continuity was preserved in many significant matters. One of the new aspects the Reformation brought was the use of the language of the people in the sermons and teaching, which created a standard for both written and spoken Finnish. The Reformation also meant a closer relationship between the church and the state. The Lutheran Church consolidated its position as the established church of the kingdom of Sweden. The incorporation of Finland into the Russian empire as a grand duchy in 1809 did not in itself alter the relation between church and state, but new legislation in 1869 created a distinction in principle between the two, in that the church received its own ecclesiastical law and church assembly. This change is still relevant today. The Finnish Evangelical Lutheran Church is not a state church but an established church to which the vast majority of the population belong and which shares in the fate of the Finnish people. The latter is above all an allusion to the events of the second world war, which led many of the pastors to appreciate more deeply this connection with the Finnish people, and helped the church to realize its own vision of working amongst the people as a church for the whole nation.

The central aspects of Lutheran Christianity are the preaching of God's word and administering of the sacraments. Eighty-four percent of the Finns belong to the ELCF. Of the children born in Finland each year, 87 percent are baptized and 89 percent of those aged 15 years attend confirmation classes. About a third of confirmed youth become young confirmed volunteers who assist in the confirmation training programme which consists of 80 lessons and a youth camp. About 16 percent of the members of the church attend a service at least once a month. The parishes place much emphasis on working with children and young people. The hymnbook was revised in 1986, and a new Finnish translation of the Bible was introduced in 1992. Particular efforts were made in 1992 to strengthen the tradition of personal evening prayers, and copies of a prayer book for the home were distributed to about 700,000 families. A new canon law governing the church's administration came into force in 1994, and a new catechism was published in 2000, of which 2.4 million copies were distributed. The books for the occasional services like baptism, weddings and funerals were renewed in 2004.

Relations between the church and the working class used to be somewhat distant in the early decades of Finnish independence. A new era of bridge-building began after the second world war. It is part of the constant preoccupation of the church to maintain contact and solidarity with all sectors of the population. The social work of the church gained new emphasis during the recession of the early 1990s, in response to the sharp rise in unemployment. This led to a broadening of its scope to cover advice on indebtedness, meals for the unemployed and the "food banks" developed in recent years, all representing new activities undertaken in conjunction with the unemployed people's own organizations.

The ELCF has gone through a learning process of its own during the years since Finland gained independence. It has begun to appreciate more clearly its role as part of the universal, undivided church of Christ at the same time as being firmly Lutheran and distinctly Finnish. The church conducts theological dialogues with other churches in Finland and has conversations with the Russian Orthodox Church. It is part of the Porvoo Statement and accepted in 1998 the Joint Declaration on the Doctrine of Justification between the Lutheran World Federation and the Roman Catholic Church. The ELCF participates in the theological work of the CPCE but has not signed the Leuenberg Agreement.